Remove unused function

image/docker/schemautil.py

@@ -1,8 +1,4 @@
 import json
-import tarfile
-
-from cachetools import lru_cache
-from io import BytesIO
 
 from image.docker.interfaces import ContentRetriever
 
@@ -26,12 +22,3 @@ class ContentRetrieverForTesting(ContentRetriever):
     digests = {}
     digests[digest] = padded_string
     return ContentRetrieverForTesting(digests)
-
-
-@lru_cache(maxsize=1)
-def generate_empty_layer_data():
-  """ Generates the layer data for an "empty" layer. """
-  with BytesIO() as f:
-    tar_file = tarfile.open(fileobj=f, mode='w|gw')
-    tar_file.close()
-    return f.getvalue()